For the piece, Bloomberg interviewed Johnson and other top Herbalife execs, toured production and distribution centers and consulted with analysts, independent research firms and market research firms.

Of all the people Bloomberg spoke to, none of them saw any red flags in how Herbalife conducts its business.

“'These stories sometimes that we’re hearing today are 20 and 30 years old,' says [Michael] Johnson. 'For God’s sake, give us a chance to change. We’ve had some mistakes along the way, but that doesn’t say we’re a corrupt organization by any means. It’s really insulting to see the stuff that’s coming out and being taken as the truth because of one person’s financial motivation.' When asked if the company has ever been a pyramid scheme, Johnson says simply, 'No.'”

Ackman, who runs $12 billion Pershing Square Capital, did not comment on the record for the Bloomberg article.

Back in December, Ackman said he is selling short more than 20 million shares, or about $1 billion worth of the stock, with a price target of $0. The premise of his bet is that he thinks Herbalife is a "pyramid scheme" and the FTC will be induced to investigate the company.

Following his presentation, Ackman's long-time rival, billionaire investor Carl Icahn, snapped up a massive long position in the company. Icahn told CNBC that Ackman would be hit with the "mother of all squeezes."

Since December 18, the trading session before Ackman publicly confirmed his short position, have risen more than 10%. It was last trading around the $47 level. The stock has trading in a range between $24.24 and $56.39 in the last 52-week period.